A standard hypodermic syringe comprises a cylindrically tubular body having a front end closed by or formed as a plug with a central throughgoing passage extending along the axis of the body and a rear end provided with a piston longitudinally axially displaceable in the body. A quantity of liquid to be injected is held in the body and a needle is fitted to the passage at its front end so that forward displacement of the piston by the plunger forces the liquid out of the body through the needle.
Such an item is typically provided as a prefilled disposable item in a hermetically sealed package. Thus it must be made at the lowest possible cost, whether it is set up for use with a simple needle cap or in a pen-type dosing injector of the type used by diabetics.